add udevmonitor, to debug netlink+udev events at the same time

This rule:
  RUN+="socket:/org/kernel/udev/monitor"

send the event to the running monitor. Running udevstart give a nice
monitor output. Also the delay between the kernel uevent and the udev
udev event can be investigated:

  pim:/home/kay/src/udev-kay # ./udevmonitor
  UEVENT[1122920113] add@/devices/pci0000:00/0000:00:1d.1/usb2/2-1
  UEVENT[1122920113] add@/devices/pci0000:00/0000:00:1d.1/usb2/2-1/2-1:1.0
  UEVENT[1122920113] add@/class/scsi_host/host12
  UEVENT[1122920113] add@/class/usb_device/usbdev2.99
  UEVENT[1122920113] add@/devices/pci0000:00/0000:00:1d.1/usb2/2-1/2-1:1.0/host12/target12:0:0/12:0:0:0
  UDEV  [1122920113] add@/devices/pci0000:00/0000:00:1d.1/usb2/2-1
  UEVENT[1122920113] add@/block/sda
  UEVENT[1122920113] add@/class/scsi_generic/sg0
  UEVENT[1122920113] add@/class/scsi_device/12:0:0:0
  UDEV  [1122920113] add@/devices/pci0000:00/0000:00:1d.1/usb2/2-1/2-1:1.0
  UDEV  [1122920113] add@/class/scsi_host/host12
  UDEV  [1122920113] add@/class/usb_device/usbdev2.99
  UDEV  [1122920113] add@/devices/pci0000:00/0000:00:1d.1/usb2/2-1/2-1:1.0/host12/target12:0:0/12:0:0:0
  UDEV  [1122920113] add@/block/sda
  UDEV  [1122920113] add@/class/scsi_generic/sg0
  UDEV  [1122920113] add@/class/scsi_device/12:0:0:0
  UEVENT[1122920115] add@/block/sda/sda1
  UDEV  [1122920115] add@/block/sda/sda1

  pim:/home/kay/src/udev-kay # ./udevmonitor --env
  UDEV  [1122920185] add@/block/sda/sda1
  ACTION=add
  DEVPATH=/block/sda/sda1
  SUBSYSTEM=block
  SEQNUM=2159
  MINOR=1
  MAJOR=8
  PHYSDEVPATH=/devices/pci0000:00/0000:00:1d.1/usb2/2-1/2-1:1.0/host13/target13:0:0/13:0:0:0
  PHYSDEVBUS=scsi
  PHYSDEVDRIVER=sd
  UDEVD_EVENT=1
  UDEV_LOG=3
  ID_VENDOR=IBM
  ID_MODEL=Memory_Key
  ID_REVISION=3.04
  ID_SERIAL=IBM_Memory_Key_0218B301030027E8
  ID_TYPE=disk
  ID_BUS=usb
  ID_PATH=usb-0218B301030027E8:0:0:0
  ID_FS_USAGE=filesystem
  ID_FS_TYPE=vfat
  ID_FS_VERSION=FAT16
  ID_FS_UUID=42D8-9E02
  ID_FS_LABEL_SAFE=s_p_c
  DEVNAME=/dev/sda1

Signed-off-by: Kay Sievers <kay.sievers@suse.de>

1 files changed, 185 insertions, 0 deletions

diff --git a/udevmonitor.c b/udevmonitor.c
new file mode 100644
index 0000000000..f4f28b1659
--- /dev/null
+++ b/udevmonitor.c
@@ -0,0 +1,185 @@
+/*
+ * udevmonitor.c
+ *
+ * Copyright (C) 2004-2005 Kay Sievers <kay.sievers@vrfy.org>
+ *
+ *	This program is free software; you can redistribute it and/or modify it
+ *	under the terms of the GNU General Public License as published by the
+ *	Free Software Foundation version 2 of the License.
+ * 
+ *	This program is distributed in the hope that it will be useful, but
+ *	WITHOUT ANY WARRANTY; without even the implied warranty of
+ *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *	General Public License for more details.
+ * 
+ *	You should have received a copy of the GNU General Public License along
+ *	with this program; if not, write to the Free Software Foundation, Inc.,
+ *	675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <fcntl.h>
+#include <time.h>
+#include <errno.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <sys/select.h>
+#include <linux/netlink.h>
+#include <asm/types.h>
+
+#include "udev.h"
+#include "udevd.h"
+
+static int uevent_netlink_sock;
+static int udev_monitor_sock;
+
+static int init_udev_monitor_socket(void)
+{
+	struct sockaddr_un saddr;
+	socklen_t addrlen;
+	const int feature_on = 1;
+	int retval;
+
+	memset(&saddr, 0x00, sizeof(saddr));
+	saddr.sun_family = AF_LOCAL;
+	/* use abstract namespace for socket path */
+	strcpy(&saddr.sun_path[1], "/org/kernel/udev/monitor");
+	addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(saddr.sun_path+1) + 1;
+
+	udev_monitor_sock = socket(AF_LOCAL, SOCK_DGRAM, 0);
+	if (udev_monitor_sock == -1) {
+		fprintf(stderr, "error getting socket, %s\n", strerror(errno));
+		return -1;
+	}
+
+	/* the bind takes care of ensuring only one copy running */
+	retval = bind(udev_monitor_sock, (struct sockaddr *) &saddr, addrlen);
+	if (retval < 0) {
+		fprintf(stderr, "bind failed, %s\n", strerror(errno));
+		close(udev_monitor_sock);
+		return -1;
+	}
+
+	/* enable receiving of the sender credentials */
+	setsockopt(udev_monitor_sock, SOL_SOCKET, SO_PASSCRED, &feature_on, sizeof(feature_on));
+
+	return 0;
+}
+
+static int init_uevent_netlink_sock(void)
+{
+	struct sockaddr_nl snl;
+	int retval;
+
+	memset(&snl, 0x00, sizeof(struct sockaddr_nl));
+	snl.nl_family = AF_NETLINK;
+	snl.nl_pid = getpid();
+	snl.nl_groups = 0xffffffff;
+
+	uevent_netlink_sock = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT);
+	if (uevent_netlink_sock == -1) {
+		fprintf(stderr, "error getting socket, %s\n", strerror(errno));
+		return -1;
+	}
+
+	retval = bind(uevent_netlink_sock, (struct sockaddr *) &snl,
+		      sizeof(struct sockaddr_nl));
+	if (retval < 0) {
+		fprintf(stderr, "bind failed, %s\n", strerror(errno));
+		close(uevent_netlink_sock);
+		uevent_netlink_sock = -1;
+		return -1;
+	}
+
+	return 0;
+}
+
+int main(int argc, char *argv[])
+{
+	int env = 0;
+	int maxsockplus;
+	fd_set readfds;
+	int retval;
+
+	if (getuid() != 0) {
+		printf("need to be root, exit\n");
+		exit(1);
+	}
+
+	if (argc == 2 && strstr(argv[1], "--env"))
+		env = 1;
+
+	init_uevent_netlink_sock();
+	init_udev_monitor_socket();
+
+	FD_ZERO(&readfds);
+	FD_SET(uevent_netlink_sock, &readfds);
+	FD_SET(udev_monitor_sock, &readfds);
+	maxsockplus = udev_monitor_sock+1;
+
+	while (1) {
+		static char buf[UEVENT_BUFFER_SIZE*2];
+		ssize_t buflen;
+		fd_set workreadfds;
+
+		buflen = 0;
+		workreadfds = readfds;
+
+		retval = select(maxsockplus, &workreadfds, NULL, NULL, NULL);
+		if (retval < 0) {
+			if (errno != EINTR)
+				fprintf(stderr, "error receiving uevent message\n");
+			continue;
+		}
+
+		if (FD_ISSET(uevent_netlink_sock, &workreadfds)) {
+			buflen = recv(uevent_netlink_sock, &buf, sizeof(buf), 0);
+			if (buflen <=  0) {
+				fprintf(stderr, "error receiving uevent message\n");
+				continue;
+			}
+			printf("UEVENT[%i] %s\n", time(NULL), buf);
+		}
+
+		if (FD_ISSET(udev_monitor_sock, &workreadfds)) {
+			buflen = recv(udev_monitor_sock, &buf, sizeof(buf), 0);
+			if (buflen <=  0) {
+				fprintf(stderr, "error receiving udev message\n");
+				continue;
+			}
+			printf("UDEV  [%i] %s\n", time(NULL), buf);
+		}
+
+		if (buflen == 0)
+			continue;
+
+		/* print environment */
+		if (env) {
+			size_t bufpos;
+
+			/* start of payload */
+			bufpos = strlen(buf) + 1;
+
+			while (bufpos < (size_t)buflen) {
+				int keylen;
+				char *key;
+
+				key = &buf[bufpos];
+				keylen = strlen(key);
+				if (keylen == 0)
+					break;
+				printf("%s\n", key);
+				bufpos += keylen + 1;
+			}
+			printf("\n");
+		}
+	}
+
+	close(uevent_netlink_sock);
+	close(udev_monitor_sock);
+	exit(1);
+}